package com.atguigu.admin.interceptor;

/**
 * @author 杨林
 * @create 2023-08-30 8:54 星期三
 * description:
 */

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * 登录检查
 *  1、配置好拦截器要拦截哪些请求
 *  2、把拦截器的配置放在容器中
 */
public class LoginInterceptor implements HandlerInterceptor {


    /**
     * 目标方法执行以前
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //登录检查逻辑
        HttpSession session = request.getSession();
        Object loginUser = session.getAttribute("loginUser");
        if (loginUser != null){
            //放行
            return true;
        }
    
        //拦截   为登录，跳转到登录页面
        session.setAttribute("msg","请登录");
//        response.sendRedirect("/");  //重定向到登录页
        request.getRequestDispatcher("/").forward(request,response);   //转发
        return false;
    }

    /**
     * 目标方法执行完成以后
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        
    }

    /**
     * 页面渲染以后
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        
    }
}

